Pull tab end for can

ABSTRACT

A pull tab can end which exposes substantially no raw edge to create a hazard to the user. The end has an orifice whose periphery is defined by a raw edge turned upward. A membrane lies over the raw edge and covers the orifice. When the end is opened, there remains a portion of the membrane on the end which surrounds the exposed raw edge, thus preventing the user from cutting himself.

O i u i United States Patent 1 n Brincks May ll, 1973 [54] PULL TAB END FOR CAN 3,610,462 10/1971 Saunders ..220/54 [75] Inventor: Richard Joseph Brincks, Wheeling,

Primary Examiner-George T. Hall [73] Assignee: American Can Company, Green- A"0mey Rbert Auber 3L wich, Conn.

22 F1 d: M 13 1972 l 1 57 ABSTRACT [21] Appl' 234065 A pull tab can end which exposes substantially no raw edge to create a hazard to the user. The end has an 52 U.S.Cl. ..220/27,220/53,220/54, orifice Whose p p y is defined y a raw edge 220/906 turned upward. A membrane lies over the raw edge 51 Int. Cl. ..B65d 17/24 and the mifm when the end is waned [58] Fi d d of Search 220/27 54 53 90 remains a portion of the membrane on the'end which 5 2 surrounds the exposed raw edge, thus preventing the user from cutting himself. [5 6] References Cited 10 Claims, 6 Drawing Figures 1 UNITED STATES PATENTS 3,281,024 10/1966 Henchert eta] ..220/90.6

PATENTEB HAY. 11973 3, 77

PULL TAB END FOR CAN BACKGROUND OF THE INVENTION The present invention relates to can ends for dispensing fluids and more particularly to a novel conends.

It has been desirable to provide cans for dispensing liquid foods or similar articles with tear strip devices which permit the opening of the can without the use of can openers. Recently, cans have been equipped with tear strips or tabs mounted on the end which are pulled away from the end exposing an opening through which the liquid contents may be poured. Such tear strips are retained in the end by partially cutting through a portion of the end made of aluminum and providing a finger engageable tab which can be pulled to tear away said portion of the end. In actual practice it has been found that the jagged, exposed raw edges of the metal result in many cuts and injuries to the user.

The instant invention is designed to eliminate the problem of exposed, raw edges by having the raw edges of the dispensing orifice upturned so that upon opening of the end, the raw edges are substantially surrounded by the remaining portion of the membrane used to close the dispensing orifice. Another advantage of the present invention is the elimination of a metal tab which might also injure consumers.

SUMMARY OF THE INVENTION The instant invention provides a can end comprising a fiat, metal panel having an orifice whose periphery is defined by a raw edge turned in the upward direction and a membrane bonded to the upwardly turned raw edge and to the portion of the exterior surface of said panel adjacent said orifice and closing said orifice, said membrane having a manually engageable tab extending I therefrom, the upwardly turned raw edge forming a sharp cutting edge against the membrane.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an unopened can end embodying the present invention.

FIG. 2 is a perspective view of the can end of FIG. 1 after it has been opened.

FIG. 3 is an enlarged, sectional view taken on the vertical plane indicated by the line 33 of FIG. 1.

FIG. 4 is an enlarged, sectional view taken on the vertical plane indicated by the line 44 of FIG. 2.

FIG. 5 is an enlarged, vertical sectional view taken on the plane indicated by the line 5-5 of FIG. 1.

FIG. 6 is an enlarged vertical sectional view taken on the plane indicated by the line 66 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Reference is now made to the drawings in describing the preferred embodiment of the instant invention. FIG. 1 illustrates a can end 11 mounted on a conventional can body 13. The end 11 comprises a flat, metal panel 15 which has an orifice 17 for dispensing the contents of the can body 13. The orifice 17 may be of anydesired size and shape, the illustrated form being substantially rectangular with rounded inner comers l9 and rounded outer corners 21. The inner portion of the struction of a pull tab and dispensing orifice for such orifice 17 is approximately in the center of the end panel 15, while the outer portion of the orifice 17 extends almost to the edge of the panel 15. The orifice 17 is pierced and formed to produce an upwardly extending raw edge 23. Such a forming process is conventional with certain types of manufacturing operations.

A membrane 25, preferably plastic, is conventionally bonded to the upwardly turned raw edge 23 and to the portion of the exterior surface of the panel 15 adjacent the orifice 17 to close said orifice 17. The membrane 25 includes a manually engageable pull tab 27 which lies free of the panel 15. When the membrane 25 is plastic, the bonding must be accomplished by heat sealing or a heat activated adhesive. If bonding is to be achieved by heat sealing, it may be desirable that at least the portion of the panel 15 contact with the membrane 25 be coated with a suitable material in order to form a very tight bond at the interface of the panel 15 and membrane 25.

The membrane 25 can be made from a variety of materials. The only requirement is that the membrane material have controlled strength properties (for reasons explained below) and, if bonding is to be achieved through heat sealing, that the basic resin is of a sufficient percentage to form a strong bond to a suitable coating or basic metal. A preferred material for the membrane 25 is a copolymer resin of polyethylene copolymerized with acrylic acid blended with inexpensive fillers such as talc and silica to reduce the cohesive properties of the basic resin.

As best seen in FIGS. 3 and 5, the membrane 25 lies over and surrounds the raw edge 23. It is necessary when the membrane 25 is plastic that said membrane 25 be heated in some manner in order that it might attain the flow characteristics required to achieve the desired surrounding of the raw edge 23.

' When it is desired to open the end panel 15, the user merely applies a pull force to the tab 27 causing the membrane 25 to break cohesively at the interface of the membrane 25 and end panel 15. This cohesive separation continues to the orifice 17 at which point the membrane 25 tears at the weakened line defined by the raw edge 23. The reason for the controlled strength properties is now apparent, since virtually all basic plastics are too rubbery and stringy to tear properly without additions of fillers to facilitate tearing. It is within the scope of the present invention that there may exist one or more layers of coating materials between the membrane 25 and end panel 15.

To understand the opening mechanism more fully, reference is made to FIG. 1, wherein there are seen two tear lines 29 completely cut through the portion of the membrane 25 adjacent the tab 27. When the pull force is applied to the tab 27, the membrane 25 cohesively separates from the panel 15 in the area between said tear lines 29. As best seen in FIG. 2, tearing and cohesive separation continue until the inner corners 19 are reached. Further application of the pull force results in tearing of the membrane 25 along the raw edge 23, which in effect creates a score line of weakening in the membrane 25 by virtue of the raw edge 23 forming a sharp, cutting edge against the membrane 25 Referring now to FIGS. 2, 4 and 6, once the panel 15 has been opened, the raw edge is substantially covered by the portion of the membrane 25 remaining bonded to the panel 15. Only the small portion of the raw edge 23 between the inner corners '19 is exposed, and since this portion is small and remote from the periphery of the panel 15, it is unlikely to be of concern to the consumer.

It should be noted that the membrane 25 could comprise a metal foil gas permeation barrier sandwiched into the membrane material, or any laminate that has low gas permeation, such as Dow Chemicals Saranex (polyvinylidene chloride sandwiched between polyethylene).

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts of the article and that changes may be made in the steps of the method described and their order of accomplishment without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

What is claimed is:

1. A can end comprising:

a flat, metal panel having an orifice whose periphery is defined by a raw edge turned in the upward direction; and

a membrane bonded to the raw edge and to the portion of the exterior surface of said panel adjacent said orifice, said membrane closing said orifice, and said membrane having a manually engageable pull tab extending therefrom, the upwardly turned raw edge forming a sharp, cutting edge against the membrane.

2. The article of claim 1 wherein the membrane is plastic and the tab lies free of the panel.

3. The article of claim 2 wherein the plastic membrane completely surrounds the raw edge.

4. The article of claim 3 further comprising means for cohesively separating the portion of the membrane between the tab and the proximate raw edge.

5. The article of claim 4 wherein said means comprises a pair of tear lines extending from the periphery of the tab proximate the raw edge to points adjacent but spaced from the raw edge.

6. The article of claim 5 wherein the membrane is bonded by a heat activated adhesive layer.

7. The article of claim 5 wherein the membrane is bonded by heat sealing.

8. The article of claim 5 wherein the plastic membrane comprises a copolymer resin of polyethylene copolymerized with acrylic acid blended with talc and silica.

9. The article of claim 1 wherein the membrane comprises plastic and a metal foil gas permeation barrier sandwiched into said plastic.

10. The article of claim 1 wherein the membrane comprises polyvinylidene chloride sandwiched between polyethylene. 

1. A can end comprising: a flat, metal panel having an orifice whose periphery is defined by a raw edge turned in the upward direction; and a membrane bonded to the raw edge and to the portion of the exterior surface of said panel adjacent said orifice, said membrane closing said orifice, and said membrane having a manually engageable pull tab extending therefrom, the upwardly turned raw edge forming a sharp, cutting edge against the membrane.
 2. The article of claim 1 wherein the membrane is plastic and the tab lies free of the panel.
 3. The article of claim 2 wherein the plastic membrane completely surrounds the raw edge.
 4. The article of claim 3 further comprising means for cohesively separating the portion of the membrane between the tab and the proximate raw edge.
 5. The article of claim 4 wherein said means comprises a pair of tear lines extending from the periphery of the tab proximate the raw edge to points adjacent but spaced from the raw edge.
 6. The article of claim 5 wherein the membrane is bonded by a heat activated adhesive layer.
 7. The article of claim 5 wherein the membrane is bonded by heat sealing.
 8. The article of claim 5 wherein the plastic membrane comprises a copolymer resin of polyethylene copolymerized with acrylic acid blended with talc and silica.
 9. The article of claim 1 wherein the membrane comprises plastic and a metal foil gas permeation barrier sandwiched into said plastic.
 10. The article of claim 1 wherein the membrane comprises polyvinylidene chloride sandwiched between polyethylene. 